Strongyloidiasis in Po valley: serological and parasitological screening in blood donors of Cremona

Backgroud. Strongyloides stercoralis is a ubiquitous nematode that is present also in Italy in a hypoendemic form, especially in the Po Valley. It is responsable for strongyloidiasis, an intestinal parasitosis usually asymptomatic or paucy-symptomatic that occasionally can cause a hyperinfestation syndrome and disseminated disease. Objectives. To determine the presence of S. stercoralis in asympomatic people afferent to the Cremona hospital by serological screening and direct microscopic search. Study Design. In the period from December 1, 2010 to June 30, 2011 we screened 154 donors with absolute eosinophilia >500/μL and percentage of eosinophils 9%. The research of anti-S. stercoralis antibodies was performed through an ELISA method (S.ratti Bordier Products). Donors positive to the screening test were tested for direct parasite search through with phormol-ethyl acetate stool concentration (FEA) and culture on S. stercoralis Agar (Biolife), Milan). Results. 13 donors were positive to the screening test (8.4%). 10 of these 13 donors performed coproparassitologic examination. S. stercoralis was identified in the stools of 3/10 tested patients through culture and in 2/10 through FEA. Conclusions. The study results are in line with the data reported in the literature for similar geographic areas. Among the risk factors are to be counted the type of job (agriculture), and the domicile in the rural environment. The culture in S. stercoralis Agar has proved much more sensitive than FEA. The serological diagnosis represent a valuable contribution to traditional coproparassitologic examination, particularlywhen screening asymptomatic individuals at risk.